5.3 Meanings and interpretations

'Applications of GIS must be carefully shaped around specific archaeological questions, themselves embedded in an explicit body of archaeological theory'
Wheatley and Gillings 2002, 237

Although coinciding viewsheds and cost-surfaces are thought to represent past meanings, the interpretation is not something that results naturally from GIS analysis, but is imposed by the researcher. Explanation processes are things that happen outside GIS; different analytical modules only perform a certain function, the result of which helps to create an explanation. The resulting map is not self-explanatory but must be explained within the relevant archaeological context. A theory-driven approach (Wheatley 1995; Lock and Harris 1996) has always been advocated in a European context  until now (Whitley, this volume).

Van Leusen insisted on the importance of interpretative choice within explanations (cf. van Leusen 1993, 113-14; Gaffney and van Leusen 1995, 370-71, 379-80). He pointed out how environmentally deterministic and cognitive models, produced by same visibility algorithms, were very similar. The general introduction of phenomenology into archaeological practice (cf. Tilley 1994) influenced the change away from deterministic models. However, discussions of perception and cognition relate more to cognitive-processual archaeology (cf. Renfrew 1992; 1994; Gaffney et al. 1996) than to phenomenological approaches. The psychological theories of Gibson (1950; 1966; 1979), the very basis of cognitive-processual perception studies, became the theoretical reference of visibility and movement studies (e.g. Wheatley and Gillings 2000; Llobera 2000). This choice of combined theoretical background has paved the way for more integrated approaches.